The broad objective of this project is an understanding of the basic metabolism of gastropod vectors of animal parasites as it relates to their biology and the biology of the intermediate stages of the parasites they harbor. Specific objectives include an elucidation of mitochondrial metabolism and how it relates to the overall energy metabolism of gastropods during different physiological states. Standard biochemical methodology is being applied to the study of mitochondria isolated from active and estivating terrestrial, semi-terrestrial and aquatic species. This includes the polarographic measurement of respiration by isolated mitochondria, its stimulation and inhibition by various compounds, and the coupling of respiration to phosphorylation. BIBLIOGRAPHIC REFERENCE: J.W. Campbell and J.E. Vorhaben (1976). Avian mitochondrial glutamine metabolism. J. Biol. Chem. 251, 781-786.